TL;DR My Raspberry Pi (Model B+) can't run the newest Raspbian (Stretch), suspected is that the kernel doesn't work. Anything with a kernel version above 4.1.19 will fail to load. Does this mean that this model is at the end of it's life or does this only happens to me?
Yesterday I did something stupid, I thought I could easily update my PHP version on my Raspberry. Now, in the basics it should be easy but I couldn't get it to work, somewhere it was suggested to update the Pi's software with
sudo apt-get upgrade. So I did that and let it be for the time being.
I went to lunch and came back to find out it crashed my Raspbian and I was unable to access it properly. To get the files back it was suggested to get another SD-card and install a new version of Raspbian (Stretch). Get a USB memory card reader and plug it into the Pi to copy my data. The idea seemed fine and it worked eventually but I could not get the Pi booted with Stretch as it turns out. The Pi showed an multi-color (rainbow) square and couldn't get passed it, tried several SD cards and none worked. I also tried NOOBS but that didn't work either.
I was suspecting that the newer Raspbian version could be a problem so I searched for a older version (Jessie, Lite). When I found the links for the Jessie versions, I tried a couple of them but some of them failed as well. I think that the problem that causes the rainbow square was most likely, the kernel version because every image with a kernel version higher than 4.1.* will fail to load but when I booted a image with kernel 4.1.19 it worked.
Now I got my Raspberry Pi back to normal but with outdated software, the apt repository seems to be outdated as well since I only get older versions of packages. I'm afraid to update the Pi again since it most likely will fail again and renders my Pi useless. With that in my mind it seems to be that my Raspberry Pi (Model b+) is at the end of it's life. What do you guys think? Are there other people with the same issues as I or are there any suggestions?